Improvement in machines for threading and pointing screw-blanks



ZSheets-Sheetl. G. R. CLARKE.

MACHINE FOR THREADING AND POIN'IINGv SCREW-BLANES. N 1754Z6- PatentedMarch 28,-,18762 N.PETERS, PHOTDLITHGRAPHER, WASHINGTON, D C

2 Sheets-Sheet 2.

G. R. CLARKE.

MACHINE FOR THREADING AND POINTING SCREW-BLANKS. No.175,426.

Patented March 2.8, 1876.

ffii

y Brooklyn,

UNrrED STATES PATENT OFFICE.

GEORGE R. CLARKE, OF BROOKLYN, NEW YORK, ASSIGNOR TO HAYWARD A. HARVEY,OF ORANGE, NEW JERSEY.

IMPROVEMENTIN MACHINES FOR THREDING AND POINTING SCREW-BLANKS.

Specification forming part of Letters'Patent N o. 175,426, dated March28, 1876 application filed February 1r 1876.

10 all whom it may concern Be it known that I, GEORGE R. CLARKE, of NewYork, have invented a certain Improvement in Machines for Threading andPointing Blanks by means of Rolling-Dies, of which the following is aspecification:

My invention relates to that class ofA machines in which screw-threadsare formed upon blanks by pressure; and it consists in the combination,with each other, of two rollingdies, rotating in the same direction, andhaving their peripheries formed into suitable shapes to impress thescrew-threads upon the blanks'introduced between them, and at the sametime to point such blanks. As my invention relates particularly to theform and arrangement of the rolling-dies, I have not deemed it necessaryto show any elaborate feeding apparatus. For the present purpose, itwill suffice to say that I propose to feed the machine by hand, makinguse of the perforations in an intermittingly-rotating disk, for thepurpose of guiding the blanks successively to the required position withreference to the dies. The accompanying drawings are as follows: Figurel is a front elevation of my machine, showing the rolling-dies mountedupon swinging bearings, and provided with cams engaging externallystationary rollers. for the purpose of regulating the distanceof one diefrom the other, and also showing the pinion for imparting motion to thegears of the die-shafts, and a portion of the face of the feed-wheel,provided with radial slots for engaging a pin upon a crank afxed to theshaft of one of the dies, by the operation of which the feed-wheel isintermittently rotated. Fig. 2 is a top view of the machine. Fig. 3 is alongitudinal vertical section through the line x a: on Fig. 2, showingthe links respectively connecting the inner ends of the die-shafts andthe intermediate shaft, and also showing one of the slotted verticalguide-bearings ofthe intermediate shaft. Fig. 4 is a transverse sectionof' one of the rolling-dies.

My machine consists of a substantial bedplate, A, provided withl twostationary uprights, c a, for carrying the stationary rollers a a',which respectively engage the feed-cams on the die shafts. Between thetwo stationary uprights are two swinging' uprights, b b, which alfordthe bearings for the shafts of the rollingdies. These uprights swing inthe same vertical plane, upon their respective pivots b b. Between theswinging uprights is the central stationary upright c, provided with aslot, c', at its upper extremity, for guiding the intermediate shaftprovided with the pinion d, which engages v the gearsc c', respectivelyaffixed to the ends of the die-shafts fand f. Power may be applied toeither ot' the die-shafts, or, as shown in the drawings, to theintermediate shaft, The intermediate shaft is linked to the die-shaft atits opposite ends by the links g and g; therefore, when the dieshaftsrecede from each other, the intermediate shaft is'lifted, and as thedie-shafts approach each other the intermediate vshaft drops downward.The slot c serves to guide the intermediate shaft in its motion up anddown, and maintain it in the same vertical plane. The dies h and h arekeyed to their respective shafts, and are each provided upon theiropposite faces with feed-cams i c, and j j. Either one or both of eachpair of feedcams may be made with a gain for gradually forcing the diestogether after their work has commenced upon the blank introducedbetween them, or, as is shown in the drawings, the working feed of thedies may be effected by only one set of cams. The 4dies are forced apartby an expanding-spring, k, the ends ot' which engage the opposite innersurfaces of the swinging arms b b. By the operation of the devices whichl have thus far described,

the dies are sprung apart at the proper time sufficiently to allow thewithdrawal of the threaded blank, and are then brought together in timeto engage another blank and form a screw-thread upon its periphery, andat the same time point it. The mode of forming the peri pheries ofthedies into the shape required to enable them to perform their functionsupon the blanks is as follows: The die-blank, which is made of softsteel, is turned upon its periphery so as to leave a beveled shoulderupon one edge. A steel screw, having a thread ofthe required shape, isthen secnrel y mounted in substantial bearings, with its axis parallelvto the 'axis of the mandrel upon which the die-blank is fastened. Thisscrew is made very hard, and is pressed very strongly against theperiphery of the die-blank, While the blank and screw are both slowlyrotated. As the blank and screw vare rmly supported so that they cannotslip endwise, the effect produced by the pressure of the screw upon theperiphery of the blank is to form thereon a series of serrations,mm,shown in Fig. 4. The end of the screul used in formingy these serrationsis on a line" with the inner end of the bevel l; therefore theserrations terminate at that point, and extend diagonally therefrom tothe opposite edge of the periphery of the die-blank. The position whichthis screw occupies in producing these serrations is shown in Fig. 4, inwhich the screw is shown in section at a. The die-blanks are bot-hformed in the sameway, by the same screw, and are therefore dupli-A'cates of each other. In operating my machine the wires or blanks uponwhich the screwthreads areto be formed are fed successively through theholes 0 o o in the feed-wheelp, which is lmounted upon the uprights p.This feed-wheel is provided with any .prescribed nulnber of holes,equidistant from each other and from the centre of the feed-wheel. Anequal number of radial slots, q 1, are cut in the face of thefeed-wheel, and these slots suc-v cessively engage the pin Ar upon theend 'of the crank r', which is affixed to the right-hand die-shaft. Asthat shaft revolves, the crank-` pin, acting upon the feed-Wheel,rotates it so as to carry forward the finished blank and bring thenexthole into the proper place tov deliver anotherl blank in position to beacted upon by the rolling-dies. The machine may be turned in eitherdirection, but it Will probl ably be more convenient .to work it byturning it in the direction indica ted by the arrow s.

l do' not confine myself to the particular organization of the machineshown in the drawings, as it is obvious various modes may be adopted forfeeding rolling-dies toward each other, or feeding a movable rolling-dieto- Ward a stationary-rolling-die. Various modes may also be adopted forfeeding blanks to the dies. Y

NVhat I claim as my invention, and desire wtows'ecure by Letters Patent,is-

l. The combination, with each other, of two rolling-dies, gearedtogether so as to rotate in vthe same direction, and having formed upontheir peripheries the bevels l, and the serrations m, for the purpose ofpointing a blank, and forming a screw-thread upon its periphery,substantially as described, such dies being provided with suitabledevices for feeding them toward and from each other, substantially asdescribed. l

2. The rolling-dies h h', each provided with the cams i and i', and theintermediate shaft d, geared and linked to the die-shafts, substantiallyas shown and described, in combination with the stationary rollers a',substantially as and for the purpose specified.

3. The pair ofrolling-dies h h', land the dieshaftj", provided with thecrank r', in combination with the feed-wheel p, having a series offeed-holes, o o o, and a corresponding series of slots, q q,substantially as and for the purpose specified.

GEO. R. CLARKE.

Witnesses:

EDWD. PAYsoN,

GEO. W. Mm'r'r.

